feat: add Lab decision policy versioning

[hyeokjun32]

Summary

• Added Lab deployment decision policy versioning with triggered rule summaries.
• Exposed policy traces in CLI, Markdown/HTML reports, demo evidence summaries, worker completion results, and Core 4 conformance checks.
• Documented the backward-compatible decision policy trace in README and the pipeline contract.

Validation

• poetry run python3 -m pytest tests/test_deployment_decision.py tests/test_worker_contract.py tests/test_api_worker_workflow.py tests/test_report_generators.py tests/test_demo_evidence_report.py tests/test_core4_conformance.py -q
• poetry run python3 -m pytest -q
• poetry run inferedgelab core4-conformance-check
• poetry run inferedgelab demo-evidence-summary --format text

Impact

• Makes Lab review/block/unknown outcomes easier to audit without changing existing deployment decision behavior.
• Strengthens the Core 4 contract smoke around Lab-owned deployment decision evidence.

Notes

• No production SaaS, DB, queue, auth, or billing behavior added.
• AIGuard remains optional diagnosis evidence; Lab remains the deployment decision owner.